Right, because I'm sure that __GFP_KMEMCG will be used in additional places outside of this patchset and it will be a shame if we have to always add #ifdef's. I see no reason why we would care if __GFP_KMEMCG was used when CONFIG_CGROUP_MEM_RES_CTLR_KMEM=n with the semantics that it as in this patchset. It's much cleaner by making it 0x0 when disabled.